Automatic electric-circuit breaker



y H. SCHACHTNER AUTOMATIC ELECTRIC CIRCUIT BREAKER Filed Aug. 19, 1926 3 She'ets-Sheet l FIG.4

INVENTOR I I I I I 1 1 I I I r 1 I I 1 1 1 1 1 1 1 I I 1 I 1 n I May 24, 1927. 1,629,640

H. SCHACHTNER AUTOMATIC ELECTRIC CIRCUIT BREAKER Filed Aug. 19, 1926 5 Sheets-Sheet 2 INVVEN TOR 1,62 4 May 1927' H. SCHACHTNER 96 0 AUTOMATIC ELECTRIC CIRCUIT BREAKER Filed Aug. 19, 1926 s Sheets-Sheet 3 INVENTOR Patented Ma '24, 1927.

UNITED STATES 1,629,640 PATENT OFFlCE.

HEINRICH BCHACH TNEB, OI MANNHEIM, BADEN, GERMANY, ASSIGNOB '10 STOTZ G. M. B. H. ABT. DEB BROWN, BOVERI & CIR, A.-G., 'OF MANNHEIM, GERMANY.

AUTOMATIC ELECTRIC-CIRCUIT BREAKER.

Application filed August 19, 1926, Serial No. 130,205, and in Germany November 8, 1824.

My invention relates to automatic electric circuit breakers of the kind in which two contact' pieces normally pressed together by springs are separated by the interposition of an "insulatin slide. According to my invention two insulating slides areused one of which is disposed below the contact pieces and is automatically interposed between the same by means of a solenoid and of a mechanical device when overload occurs, and the other slide is disposed above the contact pieces opposite to and in alignment with the first slide and is provided on a press button normally raised by spring action, in such manner that this second slide, when the button is pressed down, presses the first slide back from the cut-out position and' moves itself into position between the contact pieces and, when the press button is raised again by spring action, allows the contact pieces to be returned by their springs into the switched-on position if the overload has ceased, but allows the first slide to re-enter between the contact pieces if the overload still continues. Thus, when the overload in the apparatus ceases, switching-on can be effected by the mere pressure of the finger Without, the necessity of unscrewing the apparatus from its socket, but on the other hand, whilethe overload continues one may attempt, without danger, but without success, to switch-on the apparatus.

The cut-out movement of the first slide is commenced when the circuit is heavily overloaded, as by a short circuit, by the excitation of the solenoid coil which is included in the circuitand by the movement of the iron core of the solenoid which is thus producd, and the movement of the slide is suddenly completed by the said mechanical device which is thus set into operation. In addition to the solenoid, a thermostat may be provided consisting of a bi-metal spring and an electric heating element, which latter starts the movement of theslide when the circuit is only slightly overloaded for a fairly long period by reason of the heating action and the curvature of the bi-metal spring thereby produced. I

The accompanying drawings illustrate two forms of construction of the device embodying my invention, Figs. 1 and 2 showing a circuit breaker in the form of a safety screwplug in two sectional elevations at ri ht angles to one another, Fig. 3 showing 1; is

by a horizontally disposed partition 2. In

the upper compartment are disposed the solenoid coil 3, shown diagrammatically in the drawings, the vertically reciprocating solenoid core, which consists of two similar and parallel irons bars 4, and the slide 5, which is made of an insulating substance and is rigidly secured at its lowe r'part between the bars 4, the knife-like upper part of the slide extending above the solenoid coil 3. Furthermore, in the upper compartment two similar horn-shaped flat springs 6 (Figs. 1 to 3) are provided, or two pairs of such springs 6 (Figs. 5 and 6), which springs are held at 30 by fittings, not illustrated, on both sides of the solenoid coil 3 and bridge over this coil and the slide 5. The contacts 7 which are formed from the free upwardly bent ends of the springs 6, are pressed together by these springs in the switched-on position of the apparatus illustrated; that is to say, they come into contact in the vertical central plane of the device in which lane the edge of the slide 5 is also dispose at a short distance below the line of contact of the contacts 7.

In the lower compartment of the casing 1 are disposed the bi-metal spring 8, which is fastened at one end to the partition 2, the electric heating element 9, which is disposed adjacent the spring 8, and a mechanical de vice hereinafter described. This device consists of three parts, viz, a double armed lever 10 (Figs. 1, 2 and 4), or 11 (Fig. 5), which is pivoted to the partition'2 at 12 (Figs. 1 and 4) or to a bracket extending downwardly from the partition at 1-3 (Fig. 5), and two helical springs 14, fastened at one end to the partition 2 at 15 (Figs. 1 and 4) or at 16 (Fig. 5) and at the other end connected at 17 with the lever 10 or 11. The other end of this lever is connected by means of a link 18 to the solenoid core bars 4, which pass through a hole in the partition 2 into v to hold the lever or 11 together with the the lower compartment of the casing. In the switched-on position of the device illustrated in the drawings the axes of the springs 14 lie somewhat above the pivot pin 12 of the lever 10 (Fig. 1) or in front of the pivot pin 13 (Fig. 5), so that these springs tend solenoid core 4 and the slide 5 in this position.

If the screw-threaded plug part 19 of the casing 1 of the device is screwed into a safety socket included in an electric circuit, and if the parts of the device are in the posltion indicated in the drawings, the circuit is closed from the screw-threaded ring to the contact pin 21 in Figs. 1 and 2 through the parts 9, 3,6, 7and 6, and in Figs. 5 and 6 through the coil 3, the right hand springs pivot pin 13 of the lever 11 (Fig. 5). Consequently the springs 14 are suddenly released and draw the lever round, so that it forces the core 4 with the slide 5 upwardly.

-The knife shaped upper part of the slide 5 is thus suddeniy interposed between the contacts 7, by which the latter are separated and thus the circuit is broken.

When the overload is small the solenoid coil 3 does not act, but if the overloadcontinues longer the bi-metal spring 8 1s so heated by the heating element- 9 that it bends somewhat and thus commences the cuttingout movement of the core 4 and the slide 5. In the constructions according to Figs. 1 and 3 and according to Figs. 5 and 6 this movement is produced directly, the free end of the bi-metal spring 8 pressing the lever 10 or 11 upwardly, but in the construction according to Fig. 4 it is produced by means of a spring 22. The latter is secured at one end to the wall of the casing 1 and is normally held firmly in the position indicated in the drawing by the bi-metal spring 23 the free end of which being bent over that of the spring 22, but after sufiicient heating and bending of the spring 23 is suddenly released and strikes against the lever 10 or 11.

For switching thc apparatus onagain there is provided a press button 24, which is provided of an insulating substance and reciprocat-es vertically in a hole provided centrally in the cover plate of thecasing 1 and is raised by springs 25. By depressing this button a knife shaped slide 26 which may be formed integrally with the button and which is provided above the contacts 7 opposite to and in alignment with the slide 5 presses the latter back to the switched-on position and is itself interposed between the contacts. The springs 14 the axes of which return to a position above the pivot pin 12 or in front of the pivot pin 13 after the completion of the switchingon movement hold the parts 4 and 5 firmly in the switchedon position by means of the lever 10 or.11 when the overload has ceased, while the button 24 is again raised by the springs 25 when the pressure upon it is released and thus the springs 6 with the contacts 7 return into the switched-on position. If however the overload continues. the parts 4 and 5 are at once again raised by the solenoid coil 3 and the mechanical device, so that the slide 5, following the slide 26, again comes into position between the contacts 7 and thus prevents the apparatus from being switched on so long as the circuit is overloaded. An upwardly vextending rod 27 is fixed to the slide 5 and is provided at the upper end with a coloured pin 28. In the switched-on position this pin is disposed completely within a longitudinal hole in the press button 24, while it protrudes at the top in the switched-oil position and thus serves to indicate this position.

In addition to each pair of springs 6 there is provided a pair of metal arms 29 forming conductors which are connected to the springs at the positions 30 at which they are mounted and thence extend upwardly and inwardly at an angle their upper ends being disposed above the solenoid coil 3 and adjacent the contacts 7. In the device according to Figs. 1 and 3. in which the solenoid coil 3 and the'parts 4 to 7 are disposed laterally (in Fig. 1) in the right hand half of the compartment in the casing, the single pairof metal arms 29 are provided upon the opposite or left hand side of the coil 3. while in the device according to Figs. 5 and 6, in which the solenoid coil 3 and the parts 4 to 7 are disposed in the middle of the compartment in the casing, the two pairs ofmetal arms 29 are provided upon both sides of the solenoid coil, 2

The are or arcs which are formed between the contacts 7 upon the circuit being broken is or are directed by the magnetic field to one side or the other according to the direction of the current in the coil and in the springs by reason of the bridging over of the solenoid coil 3 by the contact springs 6 and contacts 7, that is to say in the de vice according to Figs. 1 and 3 the arc is directed laterally to the unoccupied half of the upper compartment in the casing in'the direction of current indicated by arrows in Fig. 3. while in the device according to Figs. 5 and 6 the two arcs are directed outwardly in opposite directions as indicated in Fig. 6 that is to say to both sides of the solenoid the current then passes in disposed below ea s re coil 3 towards the freespace inthe' compartment. As the metal arms 29 are provided upon the side or sides to which the are or arcs is or are directed andas-the' tact pieces normally pressed together by springs, a solenoid coil, a solenoid core, an insulating slide connected to said core and said contact pieces, a press button normally raised by spring action, and a second insulating slide provided on said press button and disposed above said contact pieces opposite to and in alignment with the first said slide, in such manner that the first said Slld6,- when overload occurs,

said solenoid coil and said solenoid core, and that said second slide,

' when said button ,is pressed down, presses and moves itselfsaid first slide back from into position between said contact pieces J and, when said spring action,

[to be re switched-on ceased, but al button is raised again byallows said [contact pieces turned by their osition if ows: said first slide to resent'er ,between said contact pieces'if the overload cuit breaker in combination =t act pieces normally springs,-, a Solenoid co 'lever. connected to said core, a spring or springs actingnpon. said lever soas to be still continues.

2. Inan automatic electric overload cirwith two 0on [pressed together by i ;released by the movement springs 6 so that is auto-'- matically interposed between said. contact ,pieces' by means of second insulating springs into thethe overload has asolenoid core, a

of said core in startingand to assist the same in completing, an insulating "slide connected to said core and disposed below said contact pieces, a press button normally raised by spring action, and a second provided on said press button and disposed above said contact pieces opposite to and in alignmentwiththe firsts-aid slide, in such manner that the first said slide, when overload occurs, is 'autoi'natically interposed between said contact pieces by means of said solenoid coil, said solenoid core, said lever and the second said spring or springs, and that said second slide,.when said button is pressed down, presses said first slide back from and moves itself into position between said contactpieces and, when said button is raised again by spring-action, allows said contact pieces to be returned by their springs into the switched-on position if the overload has ceased, but allows said first slide to re-entei'between said contact pieces it the overload still continues. I

insulating slide 3. In an autoniaticfelectric-overload cir cuit breaker in. combination-with two contact pieces normally pressed together by springs, a solenoid coil, a' solenoid core, an insulating slide connected to said core and disposed below said contact pieces, "a press button normally raised by spring action, a slide provided .on said press button and disposed above said contact pieces opposite-to and in alignment with the first said slide, a pair of metal arms, said springs and said metal arms bridging over saidsolenoid, the fixed ends of said arms being connected to those of said springs and the free ends of said arms being disposed adjacent to said contact pieces above 'said solen01d coil and said solenoid core In testimony whereof I afiix my signature.

HEINRICH ISCIH-ACHTNER. 

